Cementing boofs



UNTTED sTATEs PATENT oEErcE.

J. L. G. VARD, OF ADRIAN, MICHIGAN.

CEMENTING ROOFS.

Specification of Letters Patent No. 23,051, dated February 22, 1859-.

To all whom t may concern:

Be it known that I, J. L. Gr. VARD, of Adrian, in the county of Lenawee and State of Michigan, have invented a new and useful Improvement in Roofs; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a section of part of a roof having my invention applied. Fig. 2 is a plan of the saine.

VSimilar letters of reference indicate corresponding parts in both of the figures.

This invention consists in the covering of roofs by laying bricks or tiles in a cement consisting of an alkaline silicate and subsequently treating the surface of such cement with acid which combines with the alkali of the celnent and forms a salt which when washed away leaves a surface of pure silica which is impervious to water, thus producing a weather tight roof of a very durable character.

To enable others to put my invention in practice, I will proceed to describe its application.

The silicious cement which I employ is made by dissolving silex obtained in the form of sand, or in any form in which it eX- ists in nature, in an aqueous solution of caustic potash or caustic soda, by any process known to chemists; its consistency being such that it may be spread freely with a trowel or implement of similar character. The roof to receive this cement should be first covered with boards c, a, fitted together, and the bricks or tiles b, Z), to be used should be flat and square, or of such a form as to bed firmly on the boards and lit together so as to leave narrow parallel interstices between them. Before laying the bricks or When the cement has dried by the evaporation of its water, the whole surface of the roof is to be washed over with dilute muriatic acid or sulfuric acid which, by combining with the soda or potash, forms a muriate or sulfate of soda or potassia which, being soluble in water, may be washed away by water applied to the surface for the purpose, or will be washed away by the rst rain, and leave a surface of pure silica all over the cement; and this surface being insoluble in water is an eicient protection to the body of cement `below and also to the roof.

in described.

J. L. WARD. Witnesses:

W. TUscH, 

